Warmups

1. Write an equation in standard form: (1,2)(5,-2)

2. Find the slope and y-intercept:

6x + y = 12 y + 3 = -1(x + 1)1 2

2 5y x

QUIZ TIME!!!

Take out a pencil and Calculator Please put everything else away

6-6 Parallel and Perpendicular Lines

Objective: To identify if two lines are parallel, perpendicular or

neither

Parallel vs. Perpendicular

Parallel – Lines have the same slope // ex: -2 and -2

1 1

Perpendicular – Lines have opposite/reciprocal slopes . ex: -2 and 1

1 290°

Example 1

1. Graph the following lines on the same graph:

y = -2x + 4

y – 1 = -2(x + 1)

Are they parallel, perpendicular, or neither?

// n

Example 2

and

Then circle parallel, perpendicular or neither

12

2y x

11 ( 6)

2y x

Example 3

2x + 3y = 6 and

Then circle parallel, perpendicular or neither

33

2y x

Example 4

and y = -3x + 2

Then circle parallel, perpendicular or neither

11

3y x

Homework

Pg. 367 #18-23 & Pg. 771(6-6) #1-6

Look at the SLOPE Same = parallel Opposite (opposite sign & reciprocal) = perpendicular Neither = neither

You do not have to graph on the homework!!